2. The Functions of the circulatoryThe Functions of the circulatory
SystemSystem
1- Transport of the oxygen and nutrient1- Transport of the oxygen and nutrient
substance to the tissue.substance to the tissue.
2- Transport of the carbon dioxide and wast2- Transport of the carbon dioxide and wast
product from the tissuesproduct from the tissues
3- regulation of the body temperature3- regulation of the body temperature
4- Transport of hormones and large molecules4- Transport of hormones and large molecules
3. The parts of the circulatory systemThe parts of the circulatory system
TheThe BloodBlood vascularvascular systemsystem: which is: which is
responsible for the circulation of the bloodresponsible for the circulation of the blood
TheThe lymphlymph vascularvascular systemsystem: responsible for: responsible for
circulation of the lymphcirculation of the lymph
4. The blood vascular SystemThe blood vascular System
DefinitionDefinition: It is system of vessels through: It is system of vessels through
which the blood passes to the tissues by thewhich the blood passes to the tissues by the
continuous contraction of the heartcontinuous contraction of the heart
The blood vascular system formed of:The blood vascular system formed of:
- The heart- The heart
- The arteries- The arteries
- The veins- The veins
- The capillaries- The capillaries
5. The Basic Layers of the circulatoryThe Basic Layers of the circulatory
systemsystem
The inner layer called the tunica intimaThe inner layer called the tunica intima
The middle layer called the tunica mediaThe middle layer called the tunica media
The outer layer called the tunica adventitiaThe outer layer called the tunica adventitia
6. The HeartThe Heart
DefinitionDefinition: It is muscular organ which is: It is muscular organ which is
located at the middle of the chest. It is functionlocated at the middle of the chest. It is function
pumping of the bloodpumping of the blood
It is formed of four chambers, tow atria and towIt is formed of four chambers, tow atria and tow
ventricles they communicate withventricles they communicate with
atrioventricular orificeatrioventricular orifice
The right side of the heart carry non oxygenatedThe right side of the heart carry non oxygenated
blood and the left carry oxygenatedblood and the left carry oxygenated
7. The Histological structures of theThe Histological structures of the
heartheart
TheThe tunicatunica intimaintima: It is the inner layer called: It is the inner layer called
the endocardium it formed of simple squamusthe endocardium it formed of simple squamus
epithelium it separated from the tunica media byepithelium it separated from the tunica media by
elastic fiberselastic fibers
TheThe TunicaTunica mediamedia: called the myocardium. It: called the myocardium. It
is muscular layer formed of cardiac muscle. Itis muscular layer formed of cardiac muscle. It
thick in the ventriclesthick in the ventricles
TheThe tunicatunica adventitiaadventitia: called the epicardium: called the epicardium
formed of mesotheliumformed of mesothelium
9. The conducting system of the heartThe conducting system of the heart
DefinitionDefinition: It is formed modification of areas in: It is formed modification of areas in
the myocardium of the heart to regulate thethe myocardium of the heart to regulate the
contraction of the atria and ventriclescontraction of the atria and ventricles
The conducting system formed of Sino atrialThe conducting system formed of Sino atrial
node (S.A.N) and atrioventricular node (A.V.N)node (S.A.N) and atrioventricular node (A.V.N)
and atrio ventricular bundle (A.V.B)and atrio ventricular bundle (A.V.B)
10. The arterial systemThe arterial system
DefinitionDefinition: The arterial system carry the: The arterial system carry the
oxygenated blood from the heart to theoxygenated blood from the heart to the
capillariescapillaries
According to the size of the arteries there areAccording to the size of the arteries there are
three types :three types :
- Large arteries ( elastic arteries)Large arteries ( elastic arteries)
- Medium arteries (muscular arteries)Medium arteries (muscular arteries)
- Small arteries (arterioles)Small arteries (arterioles)
11. The histological structure of theThe histological structure of the
large arterieslarge arteries
It is formed of the three basic layers:It is formed of the three basic layers:
TheThe tunicatunica intimaintima: formed of simple squamuse: formed of simple squamuse
epithelium called the endothelium rest onepithelium called the endothelium rest on
basement membrane of elastic fibersbasement membrane of elastic fibers
TunicaTunica mediamedia: It is thick layer formed of: It is thick layer formed of
smooth muscle with elastic fibers distributedsmooth muscle with elastic fibers distributed
between itbetween it
TunicaTunica adventitiaadventitia: formed of collagen fibers: formed of collagen fibers
and small vessels called vasa vasorumand small vessels called vasa vasorum
14. The histological structure mediumThe histological structure medium
arteryartery
TunicaTunica intimaintima: formed of endothelium separated: formed of endothelium separated
from the tunica media by the internal elastic layerfrom the tunica media by the internal elastic layer
tunicatunica mediamedia: It is muscular layer of smooth muscle it: It is muscular layer of smooth muscle it
is thin than of the large arteries separated from theis thin than of the large arteries separated from the
adventitia by the external elastic layeradventitia by the external elastic layer
TunicaTunica adventitiaadventitia: formed of collagenous fibers: formed of collagenous fibers
support the artery with surrounded structuresupport the artery with surrounded structure
17. The histological structure of smallThe histological structure of small
arteriesarteries
It is the terminal branches it is diameter less than 0,3It is the terminal branches it is diameter less than 0,3
mm.mm.
TunicaTunica intimaintima: it is thin and formed of endothelium: it is thin and formed of endothelium
TunicaTunica mediamedia: formed of smooth muscle arranged: formed of smooth muscle arranged
into six layersinto six layers
TunicaTunica adventitiaadventitia: formed of collagen fibers fused: formed of collagen fibers fused
with the surrounded structurewith the surrounded structure
The flow of the blood through the capillaries isThe flow of the blood through the capillaries is
regulated mainly by this arteriesregulated mainly by this arteries
19. The capillariesThe capillaries
DefinitionDefinition: It is an inter connected thin walled: It is an inter connected thin walled
vessels through which the material exchangevessels through which the material exchange
between the blood and the tissuebetween the blood and the tissue
The blood reach the capillaries through smallThe blood reach the capillaries through small
arteries called pre capillary and leave it througharteries called pre capillary and leave it through
small venules called post venulessmall venules called post venules
20. Histological structure of capillariesHistological structure of capillaries
The wall of the capillaries is thin and formed of layer ofThe wall of the capillaries is thin and formed of layer of
endothelium of flat cells rest on basement membraneendothelium of flat cells rest on basement membrane
The capillaries formed of many types according to theThe capillaries formed of many types according to the
following:following:
The diameter of the capillaries: the are tow types.The diameter of the capillaries: the are tow types. SmallSmall
capillariescapillaries which formed most of the body capillaries.which formed most of the body capillaries.
LargeLarge capillariescapillaries has large diameter and calledhas large diameter and called
sinusoid it found in the liver, kidney and bone marrow.sinusoid it found in the liver, kidney and bone marrow.
21. Type of capillariesType of capillaries
According to the endothelium lining the capillaries: theAccording to the endothelium lining the capillaries: the
are three type of capillariesare three type of capillaries
A-A- continuouscontinuous capillariescapillaries: there is no opening: there is no opening
between the endothelium cells this type formed thebetween the endothelium cells this type formed the
most of the body capillariesmost of the body capillaries
B-B- fenestratedfenestrated capillariescapillaries: in this type there are: in this type there are
opening between the endothelium cellsopening between the endothelium cells
C-C- discontinuousdiscontinuous capillariescapillaries: part of the capillaries: part of the capillaries
formed by surrounding tissue found in the liverformed by surrounding tissue found in the liver
22. Type of capillariesType of capillaries
According to the arteriovenouse shunt: someAccording to the arteriovenouse shunt: some
capillaries has shunt to rapid the process ofcapillaries has shunt to rapid the process of
exchange of material between the blood and theexchange of material between the blood and the
tissuestissues
26. The venous systemThe venous system
The venous system carry the non oxygenatedThe venous system carry the non oxygenated
blood to the heart the veins collected to drainageblood to the heart the veins collected to drainage
at the heartat the heart
The blood passes in the venous system by theThe blood passes in the venous system by the
external pressure due to muscle contractions,external pressure due to muscle contractions,
respiration and the valves found in the veinsrespiration and the valves found in the veins
27. Histological structures of the smallHistological structures of the small
veinsveins
-- tunicatunica intimaintima: formed of endothelium and: formed of endothelium and
not contain elastic fibersnot contain elastic fibers
-- tunicatunica mediamedia: formed of tow layers of smooth: formed of tow layers of smooth
muscle and it is very thinmuscle and it is very thin
-- tunicatunica adventitiaadventitia: it is formed of collagen: it is formed of collagen
fibers connected the vein with the surroundedfibers connected the vein with the surrounded
structuresstructures
29. Histological structures of theHistological structures of the
medium veinsmedium veins
The medium veins formed by the collection ofThe medium veins formed by the collection of
the small veins and drainage into the large veinsthe small veins and drainage into the large veins
The histological structure is similar to the smallThe histological structure is similar to the small
veins but the tunica media is thicker and containveins but the tunica media is thicker and contain
elastic fiberselastic fibers
31. The large veinThe large vein
This like the femoral vein, renal vein the formedThis like the femoral vein, renal vein the formed
by the collection of the medium veinby the collection of the medium vein
It is structure similar to the medium vein but theIt is structure similar to the medium vein but the
tunica media very thick and contain collagentunica media very thick and contain collagen
fibers and the internal elastic layer may presentfibers and the internal elastic layer may present